Replacing the DC PSU

You're right. It has a thermal fuse/thermistor instead.

 

Just though I'd update with my implementation.

At first I tried using buck converters, but the 3v one overheated after 20mins or so, it should have been OK as the converter should support 3A but maybe gdemu draws more. BTW I measured max 1.35A from my 12v PSU which is great I think.



So I ended up dusting off (literally) my old picoPSU and did this:



There's a lot of room there! Everything is removable without problems and only the backside connectors are glued. I added a 5v samtec output to power up my vga2hdmi converter (Sewell Hammerhead clone) automatically when the DC is powered on, but it seems my converter doesn't receive enough power.

Anyone know if those separate 5V rails have individual or common power limitations?

Here's the lid area, just though I'd tell people there's room for stuff there. The sd-card is for homebrew and the jumper is for bios selection.



Cheers!

FG

 

That VGA adapter can be powered via pin9, I have mine powered through the Hanzo. (mine is a clone also, mini VGA2HDMI is its name.)

Also the PicoPSU should produce plenty of juice for that, if yours isn't just tap the 5v from the AV port.

 

Well, the AV port get its juice from the picoPSU so it shouldn't fix my problem... Also, I got a (overkill) 120W picoPSU so it should have enough power to handle this converter without a problem. It's supposed to provide up to 6A on both the 5V and 3V rails.

I read somewhere that the missing sound issue means the converter is underpowered, I think we got the same clone. I'm completely confused as to what could be the problem right now as there should be more than enough power available...

Thanks for the support!

FG

 

I suggested the 5v on the AV as the motherboard has already drawn power from the PicoPSU & it's just sitting there doing nothing.

Im no electrician

I use a 160 watt Pico, & I have no issues powering an external HDD from the 5v rail + the Hanzo getting its 5v & the VGA2HDMI adapter.

also the Pico I use has only 3A on 12/5 & 3v.

Running at 12v on the pico & UGC.
On the 3.3v line its 2.38A
On the 5.5v line its 1.70A
On the 12v line its 0.00A

this is my adapter.

 

That's not how it works, since the PSU sets the voltage, the current is drawn automatically given the impedance of the circuit; the load. Think of it as a faucet, the current depends on how much you turn the knob as long as you don't go over the water-tank limitations. We got the same adapter. I'll check it out when I have free time, that may be a while.

 

Are the schematics for the DC PSU available ? I was thinking of just removing the circuitry which generates the 12V.

 

I like the way you're thinking, if it is that easy

 

Japanse V0 PSU schematic

 

Thanks for the schematic madsheep!

Spoke to an electronic engineer here at work.

Simply put the 12V regulation requires a load to work properly. Either the heat is dissipated in the load or the heat will be dissipated over Q2.

Suggestions:

. Short Q2, i.e. bridge between R16 and R33 (slightly risky)
. Remove Q2 and R16

In both cases one should use a scope on the 5V and 3V3 to verify that there is no adverse effect i.e. ripple.

 

Im use psu Antec MD-135

 

I just ordered some of these connectors, have you had good luck with it so far? I'm about to install a 80w Pico and my plan is to have it be completely plug and play in case I ever want to go back to the stock psu. I'll update with pictures of my progress when I get all the supplies.

 

All my parts and tools finally arrived. This is what I've been able to get done this afternoon. I'm going to test it with the GDROM first and then swap in the GDEMU. I'll post more pictures as I finish up. I need a clean way to secure the PicoPSU, any suggestions?

 

Cable tie it to the plastic shield?

 

I fixed it with double sided tape in a small corner or the shell. Check my pictures for details.

 

I'm happy to say it works. I wont have access to my soldering iron or drill until this weekend, so I can't finish up the power switch or drill a hole for the power. My goal was to have it be able to go back to the stock power supply as easily as possible, and be able to reuse the PicoPSU if needed.

 

where did you buy the connectors?

 

Very nice. Which Pico PSU did you choose?

 

http://www.mouser.com/ , I don't recall the parts numbers. I'll have to try to find the packing slip.

 

i found the parts but did you pay 20 euros for shipping? because i don't want to pay 20 euros for 2 euro order
http://uk.mouser.com/Search/ProductDetail.aspx?R=09-50-7061
http://uk.mouser.com/Search/ProductDetail.aspx?R=08-50-0106